#include  <tr1/regex >
#include  < iostream >
#include  < string >

using namespace std;
using namespace std::tr1;

using std::tr1::regex ;
using std::tr1::cmatch ;
using std::tr1::regex_search ;
using std::cout ; 
using std::string ;

int main ()
{
	string str (" \\. a");
	regex  rgx ( str);
	cmatch match ;
	if  (std::tr1::regex_search (" aba .a",  match, rgx))
		std::cout << " match found after           "
			<< match . prefix () <<   ' \n ' ;
	return 0;
}
